Dye removal from synthetic wastewater by <i>Eichhornia crassipes</i> : a phytoremediation approach for basic fuchsin and coomassie brilliant blue R-250

This study investigates the efficient removal of basic fuchsin (B.F.) and coomassie brilliant blue R-250 (C.B.) organic dyes from synthetic wastewater using the aquatic macrophyte water hyacinth (Eichhornia crassipes). Batch experiments were systematically conducted to evaluate the adsorption capacity of Eichhornia crassipes under varying conditions. Comprehensive characterization of the plant material was performed using Field Emission Scanning Electron Microscopy (FESEM), energy dispersive spectroscopy (EDS), and Fourier Transform Infrared (FT-IR) spectroscopy, providing insights into its surface morphology and functional groups. Dye removal efficiency was critically dependent on several parameters, including initial pH, dye concentration, plant biomass, and aeration period. Optimal conditions for B.F. adsorption were identified as pH 9, an initial dye concentration of 10 mg/L, 20 g/6 L of plant biomass, and a 6-h aeration period, achieving maximum removal. For C.B., the highest removal efficiency was observed at pH 8, a dye concentration of 30 mg/L, 20 g/6 L of plant biomass, and a 3-h aeration period. These results unequivocally demonstrate the significant potential of Eichhornia crassipes as a cost-effective and environmentally benign phytoremediation agent for the effective removal of diverse organic dye pollutants from aqueous solutions. This research contributes to sustainable wastewater treatment strategies by showcasing a readily available natural resource for environmental depollution. Isotherm analysis findings confirm that the Freundlich model best describes the adsorption behavior of both dyes onto Eichhornia crassipes, reflecting the heterogeneous and multilayer nature of the biosorption surface. Moreover, C.B. exhibited more favorable and efficient adsorption than B.F., making it the more readily removed dye under the studied conditions.